The aim of this grant is to conduct the pilot research necessary to prepare the Monroe County Psychiatric Case Register for stochastic modeling of interinstitutional psychiatric histories. We will construct a path code file which accounts for a continuous stream of time (both in and out of institutions) from the registers present files which only record institutional contacts. To create the path code file decision rules must be developed to determine if a person has migrated from the county, their most likely location if there are overlapping institutional episodes, and schemes to impute missing information from surrounding records. A descriptive study of the information in the file will provide initial estimates useful for choosing among competing models in later studies. Substantive interest in this research centers aroung gaining an understanding of the patterns of interinstitutional psychiatric care. This is useful in studying the evaluation and impact of programs and policies in the context of an integrated system of mental health services rather than individual service evaluations.